Previously unpublished museum specimen records are presented for 23 species of the genus Xylocopa Latreille (Hymenoptera: Apidae) collected in portions of the countries of Bolivia, Brazil, Peru, and Venezuela within the Amazon River basin of South America. Dichotomous keys and dorsal habitus photographs are provided for the identification of females of the 13 species of Xylocopa subgenus Neoxylocopa Michener, and females of the 10 species of Xylocopa subgenus Schonnherria Lepeletier, that have been recorded to date from the Amazon River basin.